Alternative fuel sources

Electric vehicles use electricity that may well not be generated from a renewable source, and in addition, their manufacture itself is carbon intensive.

Biofuels are widely seen as the answer to the world’s growing demand for energy, but they are often very costly or come with huge trade offs.

Growing corn and sugar cane for biofuel such as ethanol can involve clearing large tracts of native forest or utilising agricultural land that would otherwise be used to grow crops for food.

There are concerns that some agrofuel production is therefore not only harmful to the environment, but may result in food shortages around the world, and higher prices for essential grains such as wheat and corn. Set against UN estimates that by 2030, the world will need at least 50% more food and 30% more water, these concerns appear warranted.

The case for biomethane

The production and transportation of biofuel derived from organic waste has no adverse impact on the environment nor does it contribute to food or water shortages around the world.

Key benefits of biomethane:

Biomethane is one of the few renewable options for fuelling heavy goods vehicles (HGVs)

Anaerobic digestion (AD) is a constant 24/7 process, unlike other renewables such as solar and wind, which are dependent on climatic conditions

Since AD generates a gas, it can be stored, unlike electricity

Food waste from landfill sites can be diverted and its energy captured efficiently

Anaerobic digestate is a by-product of the AD process, and is a nutrient-rich organic fertiliser produced without the greenhouse gas (GHG) emissions that are released during the production of inorganic fertilisers

AD produces fewer air and solid emissions than incineration, landfill, pyrolysis or gasification

At just 11g of CO2 per kWh (compared with an average of 500g of CO2 for energy from incineration), AD is clearly a low carbon energy source.

Adverse impact of organic waste in landfill sites

Organic waste is widely and plentifully available. Reducing the amount that is disposed of to landfill has a positive impact on both the environment and society:

Decaying organic waste produces methane, a greenhouse gas many times more potent than carbon dioxide, which can itself be a danger to those living in the vicinity of landfill sites

Methane gases are flammable and explosive if exposed to heat

Organic waste in landfill nourishes disease vectors such as rats and flies, particularly in improperly operated landfills which are commonly found in developing countries

Pollution of the local environment through poisonous leachate leaking from the landfill to contaminate nearby soil, groundwater and aquifers.